A centerline deviation in and of itself won't get someone fired. But hard landings aren't good. It all depends on the circumstances and if there was any damage and whether it was sufficient enough to be written up as such.

For run of the mill cruddy landings, nothing happens except a little embarassment... and bruises from the beating the CA might give the FO!

You're only in trouble unless you significantly deviate from SOP or if you break the ship... and that means both crew members. Both the FO and CA are accountable for flight safety in all phases of flight.

If it's noticeable that the rear fuselage is not fully attached to the forward fuselage, or pointing in a slightly different direction, then it's quite likely that the crew will be invited for tea and biccies with the chief pilot and retirement plans would probably form a large part of the conversation.